Re: [PATCH 1/3] ASoC: simple-card-utils: Fix device module clock

From: Sameer Pujar
Date: Sun Feb 14 2021 - 12:57:27 EST


Hi Morimoto-san,


On 2/12/2021 5:14 AM, Kuninori Morimoto wrote:
diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c
index bc0b62e..0754d70 100644
--- a/sound/soc/generic/simple-card-utils.c
+++ b/sound/soc/generic/simple-card-utils.c
@@ -173,16 +173,15 @@ int asoc_simple_parse_clk(struct device *dev,
* or device's module clock.
*/
clk = devm_get_clk_from_child(dev, node, NULL);
- if (!IS_ERR(clk)) {
- simple_dai->sysclk = clk_get_rate(clk);
+ if (IS_ERR(clk))
+ clk = devm_get_clk_from_child(dev, dlc->of_node, NULL);

+ if (!IS_ERR(clk)) {
simple_dai->clk = clk;
- } else if (!of_property_read_u32(node, "system-clock-frequency", &val)) {
+ simple_dai->sysclk = clk_get_rate(clk);
+ } else if (!of_property_read_u32(node, "system-clock-frequency",
+ &val)) {
simple_dai->sysclk = val;
- } else {
- clk = devm_get_clk_from_child(dev, dlc->of_node, NULL);
- if (!IS_ERR(clk))
- simple_dai->sysclk = clk_get_rate(clk);
}
The comment is indicating that that the clock parsing order,
but this patch exchanges it.
This comment also should be updated, I think.

/*
* Parse dai->sysclk come from "clocks = <&xxx>"
* (if system has common clock)
* or "system-clock-frequency = <xxx>"
* or device's module clock.
*/

Yes, this can be rephrased now.

asoc_simple_set_clk_rate() will be called if it has simple_dai->clk.
CPU or Codec component clock rate will be exchanged by this patch, I think.
I'm not sure the effect of this patch to existing boards.

If CPU or Codec node does not specifiy "mclk-fs" factor, asoc_simple_set_clk_rate() won't be called. So I don't think there would be any effect w.r.t clock rate. With this patch clocks would get enabled/disabled.


And also, this patch has too many unneeded exchange,
thus it was difficult to read for me.
I think it can be simply like this ?
It is understandable what it want to do.

I think the patch does exactly the same thing as what you are suggesting below. Am I missing anything?


diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c
index 8c423afb9d2e..d441890de4dc 100644
--- a/sound/soc/generic/simple-card-utils.c
+++ b/sound/soc/generic/simple-card-utils.c
@@ -168,16 +168,14 @@ int asoc_simple_parse_clk(struct device *dev,
* or device's module clock.
*/
clk = devm_get_clk_from_child(dev, node, NULL);
+ if (IS_ERR(clk))
+ clk = devm_get_clk_from_child(dev, dlc->of_node, NULL);
+
if (!IS_ERR(clk)) {
simple_dai->sysclk = clk_get_rate(clk);
-
simple_dai->clk = clk;
} else if (!of_property_read_u32(node, "system-clock-frequency", &val)) {
simple_dai->sysclk = val;
- } else {
- clk = devm_get_clk_from_child(dev, dlc->of_node, NULL);
- if (!IS_ERR(clk))
- simple_dai->sysclk = clk_get_rate(clk);
}

if (of_property_read_bool(node, "system-clock-direction-out"))